The last couple of months I have been thinking about tents. Now, if given my choice, my tent would look like and old (reenactor) wall tent, but have all the modern amenities. That means zippers, bug proofing, floor, etc. It would also be of modern canvas.
However, google drives me crazy. Trying to find real information via google is difficult to say the least. And there does not seem to be the old books about tent making about any longer either.
One of the problems is that everyone who posts on the web uses their own words to mean something different from the correct meaning. Look at seams for tents, tarps, etc. there is a lot of confusion between french seams, french felled seams, and flat felled seams. A french seam is something used in upholstery work, it has a reenforcing piece behind it and is basically a decorative top stitch. A flat felled seam is also mostly decorative, it is the seam you see on the outside of jean legs, its purpose is to not be too bulky. The french felled seam is used on tents, tarps, awnings, sails, etc. Its purpose is to be tremendously strong and water tight (in canvas). It is a double interlocked seam with double threads through 4 layers of material.
Now the problem the DIY tenters have is that the french felled seam is hard to do on a home sewing machine. At a tent or awning shop they use a french fell folder on a double needle walking foot sewing machine that folds and sews the two lines of stitching at the same time. On the other hand, the seam was originally done by hand.
I know of three ways to do it on a single needle machine. 1- fold and pin, then sew twice. 2- sew a basting seam then fold and sew twice more. 3- put the edges together with basting tape then fold and sew twice. All of those require that you roll the excess fabric on the added piece up to fit under through the machine, then turn the project over and do it again to sew the second stitch.
To be water tight (in canvas) the seam needs to be sewn with cotton, or cotton wrapped polyester, thread.
Done properly the seam is actually stronger than the fabric. Very strong across the seam, incredibly strong along the seam. Normally, you want the seams it be vertical, if they need to be horizontal the visible folded edge should be facing down. That insures the maximum water tightness.
Normally, the top and sidewalls of a wall tent would be made with one continuous piece (sewn together with the vertical seams) up and over the top and down the other side, with reinforcing at the ridge, eves, and bottoms. larger tents may have ridge and eve seams allowing smaller panels to be used. Then ends, sewn up separately, are pieced in.
I prefer the eastern woods style pitch (sometimes called military style, as it was used from the Korean War back to antiquity), with interior posts and ridge pole and side poles, to the western style a-frame or modern elk-hunter style interior steel frame.
Most of the above is as I remember from the Fieldbook I had as a Boy Scout, about a million years ago (circa 1950).